Caption/UMD and Expressions

When you create a caption in a multiview output, you can either create a caption with static text, or you can provide an expression. By default, expressions are updated every 250 milliseconds, as they cause a full re-render of the caption.

Adding Captions

1. Select the multiview you want to add a caption to in the web UI.

2. Click Edit Layout

3. Click Add Caption or press the C key.

Your caption will be added to the canvas. You can drag it around.

Every caption has the following properties.

Property Name	Description
X & Y	Sets the location of this caption.
Pad (LTRB)	Sets how much padding should be around the text in this caption. (Left, Top, Right, Bottom)
Text	If set, the static text that will be displayed in this caption.
Font	If set, the custom TTF font to use for this caption. Custom fonts can be added to the configuration file directory for Multiview.
Expression	If set, the dynamic text that will be displayed in this caption. Do not set this AND Text at the same time. Use one or the other.
Fill RGBA	The background color of this caption, given as an HTML hex color.
Font RGBA	The text color of this caption, given as an HTML hex color.
Code	The unique code of this caption. Used for updating this caption from the HTTP API.

Expressions

CAUTION: Viewports and viewers start from zero (0). The first viewer is viewer0, the second is viewer1, and so on. Same with viewports.

Category	Token Pattern	Description
System / Internal	$startuptime$	App start time UTC in HH:mm:ss
	$internal.instancename$	The platform and architecture this instance is running on. For example, `windows_x86_x64`. Includes the hostname.
	$internal.version$	The version of multiview running on this instance.
	$internal.name$	The hostname of the machine.
Clocks & Uptime	$clock24$	Local time now (HH:mm:ss), 24-hour time
	$clockutc24$	UTC time now (HH:mm:ss), 24-hour time
	$uptime$	Minutes since startup (to 1 decimal place)
Per-Viewer Diagnostics	$viewer0.diag.renderavg$	Average time to render a viewer for viewer i in ms
	$viewer0.diag.rendermax$	Max time to render a viewer in ms
	$viewer0.diag.ndiavg$	Avg NDI send wait time ms
	$viewer0.diag.ndimax$	Max NDI send wait time ms
	$viewer0.diag.hxavg$	Avg NDI|HX frame encode time ms
	$viewer0.diag.hxmax$	Max NDI|HX frame encode time msec
	$viewer0.diag.avg$	Average total time to render, encode, and send viewer to NDI
	$viewer0.diag.max$	Maximum total time to render, encode, and send viewer to NDI
Per-Viewer State	$viewer0.name$	Viewer’s human-readable name
	$viewer0.ndiactive$	“Yes”/“No” if NDI output enabled
	$viewer0.audiosource$	Audio source name or (None)
Per-Viewport State	$viewer0.viewport0.source$	NDI source name or (None)
	$viewer0.viewport0.bandwidth$	“Full Bandwidth” / “Proxy Feed”
	$viewer0.viewport0.watchdog$	“Yes” if watchdog timed out, else “No”
	$viewer0.viewport0.audio.channels$	Audio channel count or -
	$viewer0.viewport0.audio.samplerate$	Sample rate or -
	$viewer0.viewport0.audio.avgdbfs$	Peak dBFS (0.0 format) or -
	$viewer0.viewport0.preview$	“Yes”/“No” if preview tally
	$viewer0.viewport0.program$	“Yes”/“No” if program tally
	$viewer0.viewport0.tally$	“Preview”, “Program”, “Preview & Program”, or “None”